1. Field of the Invention
The present invention relates to a disk player, and, more particularly, it relates to a disk player having a disk conveying mechanism for automatically conveying a disk to a play position.
2. Background of the Invention
Heretofore, there have been known disk players for disks such as an audio disk having sound grooves on its surfaces, a digital audio disk for recording PCM signals thereon, or the like. These disk players have a disk conveying mechanism for conveying the disk to a play position while carrying the disk on a carrier capable of being projected out of or accommodated into a player housing. To convey a disk mounted on the disk carrier outside the player housing to a play position, or in other words, to position the disk on the turntable, the disk conveying has been performed by moving the disk in two directions parallel to and perpendicular to the disk carrying surface of the turntable. The disk players of this type generally have position detecting means for detecting the position of the disk in the course of the transport, that is, for detecting the position of the disk carrier. Specifically, the position detecting means include a plurality of detection switches directly or indirectly engaged with the disk carrying tray (carrier) to thereby detect both the position where the disk carrying tray begins to move and the position where the disk carrying tray terminates its movement. Recently, a structure in which the above-described disk conveying mechanism is operated with another mechanism has been often used. Accordingly, in addition to the detection switches, it is necessary to detect the position of the disk carrying tray in the course of movement. However, a problem exists in that the provision of additional detection switches increases cost. Furthermore, general switches vary in timing for the tray positions where the switches turn on or off. Accordingly, it is difficult to detect with high accuracy the position of the disk carrier in the course of movement.
There has been another proposal in which a gear engaged with a rack or the like of the disk conveying mechanism is attached to a potentiometer constituted by a variable resistor. Several comparators each compare a terminal voltage obtained by the rotation of the gear with a reference voltage adjusted and set in advance they are provided so that the change in output of the respective comparator is detected to thereby determine the position on the basis of the detection signal. In the arrangement using the potentiometer, however, as many comparators as the positions required to be detected should be provided. Furthermore, the reference voltage should be adjusted by using a potentiometer or the like, resulting in disadvantages in increased cost and in troublesome work in adjustment.